I played with this a little bit today. "Integrates with" is such a fluffy term, it's hard to know what people mean or what they're really looking for. Here's my assessment:

Scores from assignments will not pass back, so don't try to head that way.

You can embed an Edulastic assignment using an iframe tag, but Canvas cuts the width off so the students can't actually submit.

You cannot automatically create user accounts. You would either need to forward students to app.edulastic.com/login#register and enter a class code or the teacher would need to create the course roster through the account dashboard.

The Redirect Tool would allow you to add a link to your course navigation and it solves the submit problem above. You still need to create a separate assignment for students to submit in order to score their work in Canvas.